This is the most common building type for larger buildings in urban areas and the proportion is rapidly increasing. An insurer’s portfolio is very likely to include mostly properties built with reinforced concrete. The most common type of reinforced concrete structure in Turkey is the cast-in-situ reinforced concrete frame with masonry infill walls.
Typical attributes are:
Height: most are 1 to 10 storeys, but in Istanbul and other major cities, high-rise structures of 12 to 20 storeys are now increasing in numbers
Load-bearing structure: cast-in-situ reinforced concrete frame consisting of columns and beams
Wall material: horizontally perforated burned clay blocks or concrete blocks 20-30 cm thick, unreinforced
Horizontal structure: cast-in-situ reinforced concrete slabs and beams, usually with hollow fired-clay tile block infill
Roof: flat or pitched RC slabs
Steel reinforcement: older buildings have few stirrups and plain bars, newer ones have deformed bars and stirrups
Foundation: isolated footings with RC tie beams are most common, but continuous footings or raft foundations are used in loose or unstable soils
Openings: large size openings and balconies are common
Architectural layout: ground floors are often left open for car parks, or shops, especially in newer apartment buildings (soft storeys). Buildings with irregular plan shape are common due to irregular land lots and urban congestion. Frequently the columns are set back within the floor plan and are not in the plane of the external wall cladding, reducing the lateral resistance available.
Features affecting earthquake performance are: number of storeys; plan and elevation regularity; seismic design level (date of code and seismic zone); age; extent of code enforcement; quality of materials especially concrete and infill blocks; foundation conditions.